Pre-paid calling card services are well-known in the art. Such cards are typically purchased from vending machines and the like and come in fixed value increments, for example, $10, $20 and $50. A $10 card provides the customer with a certain number (e.g., 30) minutes of long distance time from any touch-tone telephone to any location in the United States, regardless of the time of the call; the $20 card provides twice that amount, and so forth. Because the long distance charges are limited to the card's face value, neither the customer nor anyone who obtains possession of the card can run up a large bill.
In operation of the prior art system, cards are batch-activated by the card provider in a limited number of predetermined values. A customer purchases one of these pre-activated cards by paying a fee. The card typically includes a predetermined identification code (which may be obscured by a scratch off material). To use the card, the customer accesses the service (usually through an 800-number), enters the identification code (typically obtained from the back of the card), dials the destination number and the call begins. Prior to dialing, the system may inform the user of a then-current card balance. If during a call the time remaining on the card is about to expire, the customer may be prompted (through a voice over) that only a certain amount of time (e.g., 30 seconds) remains. When the designated time has expired, the call is automatically terminated.
Such systems have proved commercially successful and desirable for several reasons. Pre-paid calling card customers avoid collect and operator assistance surcharges, and they can obtain long distance calling without credit and without payment of monthly bills. The cards themselves are easy to use. While the prior art systems have proven advantageous, they have somewhat limited flexibility. The most significant drawback is the requirement that pre-paid calling cards be issued in fixed or preset amounts. Also, once the time allotted to a particular calling card expires, the card is typically discarded, requiring the customer to carry multiple cards that can be stolen or lost. Existing systems do not have the flexibility to allow the customers to purchase variable amounts of calling time or to recharge "used" cards at the retail site.
There is thus a need for improved telephone pre-paid calling card systems that overcome these and other problems associated with the prior art.